[Antibacterial effect of the materials for the root canal filling, bases and material for the cavity fillings]. / Antibakterijski ucinak materijala za punjenje korijenskih kanala, podloge i ispune kaviteta.

AIM: To assess antimicrobial effects of the materials used in the endodontic treatment of the teeth. METHODS: The following root-canal fillings were examined: Ketac Endo, AH Plus, Diaket, and gutta-percha, by means of the agar diffusion test. As for the base materials, Zink Oxide/Eugenol cement, glass-ionomere cements Fuji II LC Improved, Ketac Cem, and phosphate cement and Harvard cement were investigated. Finally, of the materials for final cavity filling, amalgam, Ketac Molar and Fuji II LC Improved were tested. In the present research, the following bacteria were applied: Streptococcus mutans, Streptotoccus mitis, Lactobacillus species, Staphylococcus aureus, Enterococcusfaecalis, and polymicrobial suspention. For each individual bacterium tested, material samples were placed on the inoculated plates of blood-agar. RESULTS: Antibacterial effects were confirmed in the following materials: root-canal fillings--Diaket, AH Plus, Ketac Endo; bases--Zink Oxide/Eugenol cement, phosphat cement and Harvard cement. No antibacterial effect was established in: amalgam, gutta-percha, Fuji II LC Improved, Ketac Cem and Ketac Molar. Diaket showed a statistically more significant antibacterial effect in comparison with AH Plus, Ketac Endo, and gutta-percha (P(s.mitis) < 0.05; P(s.mutans) < 0.05; p(lactobacillus) < 0.05; p(enterococcus) < 0.05; P(staphilococcus) < 0.05; p(polymicrobial) < 0.05); of the base materials, however, a somewhat stronger antimicrobial effect was found in phosphate cement, Harvard cement, and Zink Oxide/Eugenol (ZnOE) (p < 0.05) as compared with Fuji II LC Improved and Ketac Cem. CONCLUSION: According to the results of this study, and considering the fact that all cavity-filling materials failed to show any antimicrobial effect at all, when choosing the materials for root-canal fillings, and for bases, advantage should be given to those with the manifested strongest antibacterial effect, namely Diaket and phosphate cement.

Changes in dentin after insertion of self-threading titanium pins with 3 methods: a scanning electron microscope pilot study.

STATEMENT OF PROBLEM: Inserting a self-threading pin can cause dentinal cracks, but it is not known whether dentin bonding agents can penetrate these cracks. PURPOSE: Part I of this in vitro pilot study was conducted to document the presence of dentinal cracks after the placement of self-threading pins with 3 methods. Part II was conducted to observe changes in dentin when a dentin bonding agent was applied before insertion of the self-threading pins. MATERIAL AND METHODS: The crowns of 14 noncarious third molars were sectioned horizontally 2 mm above the cemento-enamel junction, and the occlusal portions were discarded. The teeth were put into a nontransparent bag and divided randomly into 2 groups. Group 1 consisted of 12 teeth. In each tooth, 4 pinholes were prepared with a handpiece at normal rotation speed (30,000 rpm). Self-threading pins were placed into 3 of the pinholes in each tooth: 1 manually, 1 by handpiece at 7000 rpm, and 1 by handpiece at 30,000 rpm. The fourth pinhole was left empty and served as the control. All group 1 teeth were sectioned vertically through the pins, dental hard tissue, and control pin holes. The examination surface of each specimen in group 1 was polished, and the smear layer was removed with Calcinase and NaOCl solutions. After dehydration in ascending grades of alcohol, specimens were coated with a 10- to 15-nm-thick layer of gold and examined with a scanning electron microscope. In the remaining 2 teeth (group 2), a dentin bonding agent was introduced into the pinholes prior to pin placement. Two pins were placed manually and 2 by handpiece at 30,000 rpm. After pin placement, sectioning, cleaning, and dehydration, the specimens were examined with a scanning electron microscope, and x-ray mapping was performed to determine the presence of titanium, silicon, and calcium. RESULTS: Craze lines in dentin were associated with 54.5% of pins placed manually and 54.5% of pins placed with a handpiece at reduced speed (7000 rpm). Dentinal cracks were associated with 50% of pins placed with a handpiece at standard speed and with 16.7% of the control pinholes. X-ray mapping analysis revealed the presence of the dentin bonding agent between the pin and dentin wall. The dentin bonding agent was not found in the dentinal cracks except at the crack orifice. SUMMARY: Within the limitations of this pilot study, the method of pin insertion had no direct bearing on the presence of dentinal cracks. The dentin bonding agent tested did not fill the entire space of dentinal cracks but did occlude their orifices and fill the spaces between pin surface and dentin walls in the pin preparation.